Stevia rebaudiana is a plant which is known to contain sweet tasting compounds, including stevioside and rebaudioside A. These compounds are currently being used as sugar substitutes in a number of foodstuffs, including soft drinks A detailed report regarding their safety, toxicology and metabolism may be found in Food and Chemical Toxicology 2008 vol 46(7), Supplement 1, where the entire supplement is devoted to rebaudioside A as used in food and beverages. Stevioside and rebaudioside A are metabolized into the aglycone steviol, a compound which is not sweet.
JP 10265347 (Shiseido Co., Ltd) describes an agent which prolongs the growth period of the hair cycle and can be made from a number of plant extracts, including comfrey (Symphytum officionale L.), Curcuma domestica, jujube tree (Zizyphus jujube), Keirin wild ginger (Asarum sieboldii), coix seed (Coix lachryma), Stevia, cube gambir (Uncariagambir roxburgh), gentian (Gentiana lutea), hops (Humulus lupus), Isodon japonicus, and azuki bean (Azukia angularis), in addition to a number of other plants.
EP 1 666 036 discloses a hair growth stimulant containing a chromene compound, such as methylripariochromeme A, acetovanillochromene, or orthochromene. Chromene compounds may be extracted from some Stevia species, in addition to other plant genera and species. Chromenes are not structurally related to steviosides or steviol.
There is a need in the art for a hair care composition which can enhance the natural health and beauty of the hair, which can restore hair growth and prevent hair loss/thinning due to aging, and which can be orally ingested.